Method of making interlocking joints.



M. GUETT.

} METHOD OF MAKING INTERLOGKING JOINTS.

APPLIOATIQN FILED 0OT.16, 1906.

935,970. Patented 0011.5,1909.

Z11 i" i 'ljw [9 i- I 1 60 IE 'i I w vfi 5 UNITED STATES PATENT OFFICE.

MONROE GUETT, OF HARTFORD, CONNECTICUT, ASSIGNOR TO THE HART & HEGEMAN MANUFACTURING COMPANY, OF HARTFORD, CONNECTICUT, A CORPORATION OF CONNECTICUT.

METHOD OF MAKING INTERLOCKING JOINTS.

To all whom it may concern:

Be it known that I, MONROE GUETT, a citi- Zen of the United States of America, residing at Hart-ford, in the county of Hartford and State of Connecticut, have invented certain new and useful Improvements in Methods of Making Interlocking Joints, of which the following is a specification.

The object of my invention is to produce a metallic box of novel construction and to provide a novel method of manufacturing the same.

Boxes of this sort, called wall boxes, are used to a considerable extent in electrical work for the installation of switches, etc.

In the drawingsFigure l is a side elevation of a box embodying my invention. Figs. 2 and 2 are detail views of parts of the completed box. Fig. 3 is a plan view of the box and the roller for upsetting the tenons. Fig. 4 is a perspective view of the finished box. Figs. 5 and 5 are detail views similar to Figs. 2 and 2*, but before the upsetting operation.

As will be seen from the drawings the side walls and end walls of the box are flat plates at a with tenons Z) Z) on their edges, the tenons on the edges of adjoining sides being staggered so as to fit together and make a square joint. These tenons are made slightly longer than the thickness of the metal, as indicated in Figs. 5 and 5, so that they can be upset endwise to lap over the tenons on the adjoining sides, as indicated in Figs. 2 and 2, thus locking the walls securely together.

The tenons on the edges of adjoining walls are upset simultaneously, preferably by means of a roll 0 having a right-angle groove 0 in its face. In this manner the sides are Specification of Letters Patent.

Application filed October 16, 1906.

Patented Oct. 5, 1909. Serial No. 339,195.

forced together during the upsetting operation, resulting in a firm solid joint.

The tenons are formed by blanking out the side walls in a suitable press, and consequently the fit of the tenons in the spaces in the edges of the adjoining side is just free enough to allow the metal to spread, giving the tenons a dovetail shape, with the result that the corners of the box will be perfectly flush with the walls. v

A bottom can be inserted when the box is assembled.

This method of construction produces a box which is extremely simple and inexpensive in its construction and which has smooth exterior and interior surfaces, with all the advantages of a box drawn up to shape from a single piece of metal.

I claim as my invention:

The method of making an interlocked joint which consists in assembling a plurality of members so that they lie at angles to each other, said members having interengaging tenons which are slightly greater in length than the thickness of the adjacent walls, and then subjecting the ends of said tenons to the action of an upsetting roll which has a grooved working portion on its periphery and the side walls of which make an angle with respect to each other which is substan tially the same as that made by the said members.

In testimony whereof I aflix my signature in presence of two witnesses.

MONROE GUETT.

Witnesses:

A. E. PARSONS, E. C. SWAN. 

